Electronic ink is content added to an electronic document based upon a user input technique where the user handwrites, draws, or performs other arbitrary spatial movements. As a result of such user input, visual marks are added to the document that correspond to the path of the movement. For example, in the case of handwriting, handwritten words appear in the document in the same handwriting style that they were executed by the user.
In some cases, the user performs this input by moving a stylus or his or her finger across the surface of the display device on which the document is displayed. In such cases, the electronic ink generally appears in the document in the positions where the interactions occurred. In some cases, the user performs the inking input by moving a displayed position pointer on the screen, using an input device such as a mouse or touchpad.
In the case of electronic ink corresponding to handwriting, handwriting recognition techniques can be used to identify text represented by the handwriting, which can be inserted in the document along with or in place of the electronic ink handwriting.
Ink is generally consumed by application programs that register to receive it. In such a case, it is typical for an ink-aware operating system to process ink-related input events to do some or all of the following automatically on behalf of the registered application: generating ink—that is, creating the data structures representing ink, including strokes interpolated and/or smoothed from a sequence of points along a movement path; rendering ink—that is, causing a visual representation of ink to be displayed in the application's display area; and/or “drying” ink by transferring the data structures that represent it to the control of the application.